Recently, the field of the nanotechnology is noted. This field is of technologies utilizing phenomena invisible or unrealizable in the macro-state by using nanometer-sized substances and particles. Among these technologies, memory devices which store charges in nanodots or nanoparticles to thereby memorize information are proposed.
As the typical memory device using nanodots and nanoparticles, the memory device using silicon nanocrystals is noted. The memory device using silicon nanocrystals comprises silicon particles formed in an insulating film over a silicon substrate store charges in the particles to make memory operations.
The memory devices using nanodots and nanoparticles are described in, e.g., Patent Reference 1 to 3.
Patent Reference 1: Japanese published unexamined patent application No. Hei 11-040809
Patent Reference 2: Japanese published unexamined patent application No. 2000-022005
Patent Reference 3: Japanese published unexamined patent application No. 2004-111734